Lubricating oil composition



Patented Jan. 19,1954 2,666,746

2,666,746 LUBRIcA'riNGofi. COMPOSITION John C. 'Munday, iCranfo'rd, and Dilworth T. Biigers,=Sulnmit, N. J.,-assignors10.;Standard OiI DeVcIGpm'ent Company, a, corporation 0! I Delaware" V l No Drawing Application August 11, 1952,

crial Not-1303327 I {beams (tilts- 6) a 1 r t 2 7 This inventiumltelatfls.IQAQY LQh miQQJQPI h m l h may be d such as 0 nets and to processes or ai i ami using decyl. acetyh octa e v as Well s r, mi same. More particularly, igh f '"tureS such: s-- m u e 0f W e yl molecular weight ;t;copqlyrners rent *cwithfcetyL-or octadecyl, -anda mixture q of t one being an F08, 1610, C12," C r;-G1s-=and Cm alcohols having an 1 niaverage'inthe C11G14 Ia.nge.- Even some of the alcohols having less than 8 carbon atoms, -e.- g., p-hexyl, am-yl, or-;even-lower may; be used,-pro- 'rviding that a sufficient amount of higher alcohols having for instance 12 to 18 carbon atoms, are also used-to make -a total mixed alcohol product b en suggested to make lubriaveraging at least as high as -8 carbon atoms and b "po lyrn erifiatioii of several preferably averaging about to is carbon atoms. aturated esters, and some When the alcohols-in the fumarate ester average ggestejdf Howevenmany -'aboVeabout'C12,-for example about (313,5 as in tipscrcobmym a "or onefre as'on' or'other -:=I:i 1-B. ec q rs are pour depressants as r 'unsatisfactory;"Torunstaric, some are insoluble given as --V. Ir-improvers. Shorteralcohols, for

inr lubricating 0115 especially highly paraftlnic "example decyl andoctyl in thefumarate ester "oils'aii'd b'ut: inferior as'p'our give fumarate-vmyl copolymers; which are exdepressants an viscosltyinde improvers. r lational-V: L improvers, but have littleOr no Broadly, thepresent-inventioncomprises the I a uproductionpf;copolymers of a fumaric acid ester Inpreparine the fumaric acid ester which may of one or moresaturatedalcoholshaving about 8 alsebe; called analkylf umarate, direct esterifiv-to- 18 carbon atomsi with a vinyl ester or a fatty cation of fumaric acid with an alcohol is pre- -v; A 2 t V H a 2 ferred, H0wever, ester interchange between a The alcohol of theiumarateester maybe :a v i 2 a v p a ate such as methyl orethyl or singliliindividual alcohol, especially one such as V amyl iumarate and. a higheralcoholof the de- Yfthe '(fitldecYD-or iilllf 'fif l) '9 Qi jfil' fili ffiqfi fiffiiredtypei ze-i -i e hav n 8 to 18 carbon atoms alcohol.---'A-if i xturej of'two or more alcohols havor so, or Lorol B, may also be employed.v The vif"ifl'garl'efire'rage nu be!"ofcarbonatomsranging ester nterchange-may be carried substantially from "stasis 8 "to "18 and "preferam "averaging 1 to; completion, or tonly partly so. In the latter about '10 to 14.carboniatomsimay also beemp Y. ase pi dl fi ll: contain mixed esters 3. in the-.Iumarate ."cstermiOni-igiyeryisuitablg coma ',m y *-L0rq1B f umarate.

yrmercially availablelmixed alcohol; a product I The other primary reactant to be copolymerized i -1 obtainedz.by;hydrogenation,otvcocoanutwith the' above described alkyl fumarate esters, puavproduct js'js'old undcnthemgmgg is the vinyl ester of alower fatty acid, prefer- 1 waanuitis:atmixtureiof:saturat.ed aie 1 c b yg l fi t an. 20 carbon atomsl ialcohols o'i alkanolsman ins'iro t ei the preferred vinyl ester, a ho h o ii carbon atoms, ibutthavinesa 1 ,439

may also use vinyl esters of other acids such as lauryl alcohol which has 12; carbon atom Qther "-prop 0ni butyr c lauric, t a t c, tc itrelated rproductsialrepma fit :bv.:.senar t e i I pour depressant action.

such as-the vinyl ester of cocoanut oil acids.

material, whichiin'lay b icrude i The-proportionsfin which these'two reactants, 'mixture,.j into ."s'evera il gnamely theal-kyl fumarate and the vinyl tester,

ea;;;relatively..;higher2 r imrhigher or lower or,=me

-. The .comPQSition so; 4 the Lerolj;

related productsicalledfLoro is. appr'oximatelyi SiLfOllOWS 1 emcee "mew the are copolym erizedmaybe -varied;overa fairly eof. 1 wide range ,Forexample; the mol ratioof alkyl furnarate to vinyl ester-maybe in the range from l/0. 2 to 1/ 6,-,pr eferably about 1/0.5 to l/5,which generallycorr.esponds to a weight'ratio in the range frQm ZO /L to 1/ 1. The proportions em- :-;-p1oyed depend somewhat on the particular fu- 117? i 1 r -marate and vinyl esters which are copolymerr ized. For example, octyl iumarate-rvinylacetate V I copolymerv-of; 15300-20300 'moleculareweight "may be insoluble in some oils if more than about z one mol of vinyl acetate per mol of fumarate is employed, whereas with 0.6 or 0.8 mol of vinyl acetate this difficulty is not encountered, 'With higher fumarate's greater amounts of vinyl acetate can be: employed, for example 2 or 3 mols per mol Of decyl ,fu marate, Or 5 or'fi ormore n'ciols perjfmol-of octadecyl fumarate. 'A' similar Average number of carbon I 812011182125; .\.-.V.-.-

situation exists with respect to the vinyl ester, in that greater amounts of vinyl esters such as vinyl butyrate and vinyl laurate can be employed than of vinyl esters of short chain acids, for example vinyl acetate.

In carrying out the copolymerization the two reactants may be mixed and the mixture heated with or without a solvent or diluent, and preferably with a small amount of catalyst, to a reaction temperature of about 50 to 125 0., preferably about 60 to 100 C., using, if necessary, either superatmospheric pressure or refluxing, to prevent los of reactants by vaporization. Adequate cooling should be provided to absorb the heat of polymerization. It is often convenient, especially when employing large proportions of vinyl ester, to add the latter gradually rather than all 7: at once, thus controlling polymerization rate.

As catalyst, it is found suitable to use about 0.1 to 5.0%, for example 1.0% by weight of a peroxide such as benzoyl peroxide, acetyl peroxide, t-butyl hydroperoxide, t-butyl perbenzoate, etc.

The reaction time will vary for instance from about 1 to 100 hours, preferably about to 20 hours, varying inversely with the temperature. The molecular weight should be from about 1,000 to 50,000 or more, but preferably from about 3,000 to 30,000 for best results from a pour depressing point of view. When employed as viscosity index improvers, copolymer molecular weights from about 8,000 to 20,000 are preferred. The molecular weight may be controlled by the use of a solvent or diluent, such as n-heptane or other inert liquid such as petroleum ether, refined naphtha, kerosene, lubricating oil, etc., copolymers of higher molecular weights being obtained with lesser amounts of solvent or none at all.

During the copolymerization it is preferred to exclude oxygen or air by any suitable means such as by blowing the reaction mixture or the reaction vessel with an inert gas such as nitrogen or carbon dioxide.

The copolymers of this invention may be used as lubricating oil additives, in concentrations ranging for instance from about .05% to 5% or more. Preferably from about 0.1% to 0.5% is used when pour depressing is the primary object, and a larger concentration for example from 0.5% to 10% when V. I. improvement is the primary object. The oil basestock in which the copolymers may be usedmay be not only the paraifinic oils which require pour depressors, but also naphthenic or mixed base lubricating oils which are desired to be improved in viscosity index, or blends of various types of oils where substantial improvements in both pour depressing and V. I. improvement are desired. The copolymers may also be used in greases which contain metal soaps, or in parafiin wax or waxy compositions, or in lighterliquid hydrocarbon oil products such a diesel fuel basestocks, which are often highly parafl'inic in nature and require pour depressing, or other light oils such as domestic heating oil basestocks, mineral seal oil, refined kerosene and the like.

In preparing the lubricating oil or other compositions containing the novel copolymer of this invention, one may also add other conventional additives such as dyes, anti-oxidants, etc., or one may add other types of pour depressors such as the wax-naphthalene condensation product previously referred to or others such as a wax-phenol condensation product, as well as other viscosity index improvers such as polybutene, polyacry- 1 4- lates, e. g. poly lauryl 'methacrylate, polyvinyl ethers, polyvinyl esters, etc.

The invention will be better understood from a consideration of the following examples.

7 EXAMPLE I amount of benzoyl peroxide a catalyst, the exact amounts of materials used being as follows:

650 g. Lorol B fumarate (1.31 mols) 113 g. vinyl acetate (1.31 mols) cc. n-heptane 7.63 g. 60 mesh benzoyl peroxide Table I .-Pour point depression by Lorol B fumarate-vinyl acetate copolymer ASTM'pour point F.)

Weight percent copolymer 011A Oil B 011 C fumarate alone was blended in 0.2% concentration in the same three oil basestocks A, B and C. The ASTM pour point was -15 F. in each case, whereas applicants copolymer gave 20, 25 and below 35 F. respectively.

Another unobvicus advantage of the present invention is that the copolymers produced not only are goodv pour depressors when tested by the ASTM pour point procedure but also have good pour stability as determined by a laboratory test intended to simulate field storage conditions in which the blends being tested are subjected to alternate cycles of cooling and warming. In this pour stability test a blend'of 0.2% of the Lorol B" fumarate-vinyl'acetate copolymer de scribed above, in Oil 0 basestock, showed a stable pour point below -10 F., whereas a similar concentration of a commercially available pour depressor 'of' the "wax-naphthalene'---condensation product type, went solid at F; mule same pour stability test.

. Various concentrations of the '7,100 -molecular weightcopolymer described above; and also of a 19,600 mo1eculafr weight copolymer prepared Slmiilaflyiwere tested "in Oil A' basestoclt for viscosity index improvement, with the rsultsshown in Copolymer I. I, "molecular: Ytffgji Wei glitfpercent 1 weight The datafin the Table 11 indicate that the viscosity index of a parafiinic lubricating oil basestockcan easily beraised from 114 to 130 or.140

or even higher by the fadditionof smalla mounts of fumarate-vinyl ester copolymers.

EXAMPLE '11 .Octyl furnarate and vinyl acetate were copolymr ized'at 68 'C. in thepresence of 1.0 weight pie ceht':ofbenzoy1' peroxide catalyst. The 'fu- The copolymer was not a pour 6 :The client .of increasing the proportion of viny1 ester was determined by employing twomols of vinyl acetate per mol of decyl fumarate. In this case a :blend of 1.8 weight percent ,ofkcopolymer in Oil .A'ha'd a viscosity .at .210" F. of only 54.3 anda viscosity index of 140. Theadvantage-of employing the larger portion of vinyl acetatev is apparent,since less thickening ofthe base roiL occurred when :the copolymer was pre pared with two mols of .vinyl acetate. This rend has also beenobserved 111113116 ..case of other ifumarateevinyl oestervcopolymers, for example, those of :L orol 'fumarat'e and-vinyl acetate prepared in 1'/2 .fumurate/vinyl-acetate mol ratio.

FEXTA PEE I To investigate he efiecto inc easin the chain. len t of 3th inylest r comp nent of the op lvme s of in n io ta'ddi a opo yniersvofthe ,LorolB ester;of,-fumaric acid were pre a ed w h= iny aceta e ny butyra aand vinyl laurate, that;i s, using vinyl esters of fatty acids -c o taini,ng *2, 4 and 12 carbon atoms, respectively. Ifhe copolymers were prepared using equal mols of the ;fumarate ester and the vinyl ester, us ing n-heptane as a diluent (a 4:1 ratio of monomers to heptane :by weight), using as va catal st L0 w i htr r .cento benzovl p x d a em e a ure 191 1 10-, and a re c ion m of Qll i The .lte ul-ti o vm.o s wer s pa d f m un e ted y nir iesterandsiiluentas i inExample I above. I

The copolymeric additives prepared as described above were blended in 0.1 and 0.2 weight v per cent in both Oil A and Oil-C as in Table I above. Oil A was identical with Oil A above except that it was less stringently de-waxed and of exceptional characteristics, giving high viseosity indices with relatively little increase in viscosity. Another copolymer prepared similarly but employing a fumarate/vinyl mol ratio of 1/ 1, had a molecular weight of 14,000. Blends of the two copolymers in'Oil A had the viscosities and viscosity indices shown in Table III.

Table [HY-Viscosity index improvement by octyl jumamte-oinyl acetate copolymers Viscosity (Saybolt sec- Weight percent Molecular onds) Viscosity copolymer .wclght index EXAMPLE III Decylfumarateand vinyl acetate were copo1y-. merized at 70 C., employing 1.0 weight per cent benzoyl peroxide catalyst, nitrogen atmosphere, 16 hour reaction time, 72.5 volume per cent monomer concentration in n-heptane diluent, and a fumarate/vinyl mol ratio of 1/1. The molecu-.

had a pour point of 15 F. instead of 5 F. as in Table I. Results of the standard ASTM pour point determinations are set out in Table IV below:

Table IV ASTM pour points F.)

Vinyl ester used on A( 0110 Vinyl scouted +15 -20 20 +30 -15 -25 Vinylbutyr e-.- +15 -15 -25 +30 -25 -25 Vmyllaurate +15 15 15 +30 --15 ---15 It is not intended that this invention be limited to'the specific materials which have been mentioned merely for the sake of illustration but only by the appendedclaims in which it is intended to claim all novelty inherent in the invention as well as all modifications coming with- I in the scope and spirit of the invention.

This application is a continuation-in-part of Serial No. 653,177, filed March 8, 1946, for the sameinventors, now abandoned.

What is claimed is: 1. A lubricating oil composition comprising a major proportion of mineral oil and a small amount, sufficient to depress the pour point thereof, of an oil-soluble copolymer of a vinylester'of a fatty acid having from 2 to 18 carbon atoms and a dialkyl fumarate wherein each alkyl group ranges from not less than 10 to not more than 18 carbon atoms.

2. A lubricating oil composition comprising a major proportion of mineral oil and a small amount, sufficient to depress the pour point thereof, of an oil-soluble copolymer of vinyl acetate and a dialkyl fumarate. wherein each alkyl group ranges from not less than 10 to not more than 18 carbon atoms.

3. A lubricating oil composition comprising a major proportion of mineral oil and a small amount, sufficient to depress the pour point thereof, of an oil-soluble copolymer of a vinyl butyrate and a dialkyl fumarate wherein each alkyl group ranges from not less than 10 to not more than 18 carbon atoms.

4. A lubricating oil composition comprising a major proportion of mineral oil and a small amount, sumcient to depress the pour point thereof, of an oil-soluble copolymer of vinyl laurate and a dialkyl fumarate wherein each alkyl group ranges from not less than 10 to not more than '18 carbonatoms.

5. A lubricating composition which comprises a major proportion of a waxy mineral oil base stock having combined therein from 0.01% to 5.0% by weight of a copolymer of about 1 mol 0 of a dialkyl fumarate of alcohols averaging about 10 to 14 carbon atoms with about 0.2 to 6.0 mols of vinyl acetate, said lubricating composition having an improved pour point.

6. A lubricating composition comprising a. major amount of a waxy mineral oil base stock having combined therein about .0 to 5.0% by weight of a copolymer having a molecular weight of from about 1,000 to about 50,000, said copolymer being formed from about 1 mol of a dialkyl fumarate of alcohols having from 10 to 14 carbon atoms and about 0.8 to about 2.0 mols of vinyl acetate.

7. A lubricating oil composition having improved pour point characteristics which comprises a major amount of a waxy mineral oil base stock and from 0.01 to 5.0% by weight of a copolymer having a molecular weight of about 5,000 to 20,000, said copolymer being formed from substantially equimolar proportions'of vinyl acetate and a di-alkyl fumarate of the mixed alcohols obtained upon hydrogenation of cocoanut oil, said mixture of alcohols having an average number of carbon atoms in the order of 13.5.

8. A lubricating oil composition comprising a major proportion of mineral oil containing combined therein from 0.01% to 10.0% by weight of an oil soluble co-polymer of a vinyl ester of a fatty acid having from'2 to 18 carbon atoms, and a dialkyl fumarate wherein each alkyl group ranges from not less than 8 to not more than 18 carbon atoms.

JOHN C. MUNDAY. DILWORTH T. ROGERS.

References Cited in the file of this patent UNITED STATES PATENTS 2,628,198 Arundale et a1. Feb. 10, 1953 

1. A LUBRICATING OIL COMPOSITION COMPRISING A MAJOR PROPORTION OF MINERAL OIL AND A SMALL AMOUNT, SUFFICIENT TO DEPRESS THE POUR POINT THEREOF, OF AN OIL-SOLUBLE COPOLYMER OF A VINYL ESTER OF A FATTY ACID HAVING FROM 2 TO 18 CARBON ATOMS AND A DIALKYL FURMARATE WHEREIN EACH ALKYL GROUP RANGES FROM NOT LESS THAN 10 TO NOT MORE THAN 18 CARBON ATOMS. 